Method of repairing cracked or broken structures by electric welding



Nov. 3, 1925. l

, R. MATTICE METHOD or nsgpnxuo CRACKED on BROKEN STRUCTURES BY mzcmzc WELDING Orizinal Filed Oct. 3. 1924 gmentoz Patented Nov. 3,. 1925.

uurrao STATES PATENT OFFICE.

ROYAL IATTICE, OI BETHLEHEM, PENNSYLVANIA.

Application fled October 8, 1924, Serial F0. 741,494. Renewed September 26, 1925.

To all whom it may convent:

Be it known that I, ROYAL MATTICE, a

citizen of the United States, residing at Bethlehem, in the county of Northampton and State of Pennsylvania, have invented certain new and useful Improvements in Methodsijof Repairing Cracked or Broken Structures by Electric Welding, of which the following is a specification.

This invention relates to the method of repairing cracked or broken structures by welding and has particular reference to-the repair of double walled structures generall While this invention has been practiced specifically in the repair of cracked or broken tops of hot blast stoves and the drawings showgenerally such a' structure, it is obvious that the herein disclosed method is adaptable for the repair of any double 'walled structure, and I desire it understood that this invention is not restricted solely and a plate then clamped over the repaired surface by screws or the like. This method proved unsatisfactory.

In the case of hot blast stove ,tops,-the type illustrated being double walled, if the crack appeared in the lower section it has heretofore been almost an impossibility to repair the same chiefly because of the fact that there is only about three inches between the walls.

It is therefore one object of this invention to provide a method for the repair of cracked double walled structures.

It is a further object of this invention to provide a method for repairing cracked or roken hot blast stove tops.

It is a still further object of this invention I to provide a method'of repairing cracked or broken double walled structures such as .iot blast stove tops or the like by electric weldg Other objects and advantages of this invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which:

Figure 1 is a sectional view of a hot blast stove top.

Figure 2 is-ii fragmentary front elevation, partly. in section, of another portion of a stove top:

Referring-now more particularly to the drawings, A designates a hot blast stove top in its entirety, the same comprising an up-- per section 1, a lower section 2 and a stack 3; the latter secured to section 1 by bolts 4 or the like.

' xn'mon or surname cnacxan on anoxnn srnuc'ruaas BY anaemic WELDING.

The upper and lower sections 1 and 2 are spaced from each other a distance of approximately three inches, in stoves of present day usage, and the upper section 1 is supported by means of a plurality of webs 5, each provided with a brace 6. It is to be understood of course that both the sections 1 and 2 are provided with a central opening, communicating with stack 3, and that braces ii are substantially arcuatc in shape and are spaced each from the other, circumfcrcntially around the opening.

It has been found that due to expansion and contraction, the upper sections 1 imd 2 crack. and also that braces G and webs 5 often crack.

in Figure 1 reference characters 7 designatc cracks in section 2. 8 designates a crack in section 1, and 9' designates cracks in brace 6.

Referring to Figure 3, where is shown the method of repairing section 2 when cracked as shown at 7, in Fig. 1, it will be apparent that because of the very small space between sections 1 and 2 it is difficult to make a satisfactory repair of the cracked surface. In view of this the first step in my method is to remove a portion of section 1 by any suitable means, such as, an oxyacetylene torch, the section 10 shown in Figure 3 being nemovcd thus exposing the crack 7. If only section 2 is cracked a portion of the metal of section 1 immediately above the crack is removed,- and if both sections 1 and 2 are cracked a portion of section 1 above the crack in section 2 and including the cracked metal of section 1 is removed. I As the next step in my method, I cut a V in the metal of section 2, or in other words I remove a "portion of section 2. forming an opening therethroughflhe portion removed including the metal in which the crack appears. The opening rovided is indicated etween the ClOtiSELlllllQS 11 in Figure 8, such opening being of sufficient size to permit pad 12 to be) inserted through the opening and held in place against the lower face of section 2, covering the opening just formed. The pad 12 is held thereagains-t by any suitable means and I then weld the opening indicated between lines 11, preferably by electric welding, the opening being completely filled as shown at'l3. The weld forms with section 2 and pad 12, an integral structure and the formerly cracked section 2 has now been repaired. It is obvious that any surplus metal 03. the weld may be removed by any suitable means.

As a final step in this method, I chamfer the edge of section 1 at the opening formed by the removal of portion 10 and i1 portion 10 is a sound piece of metal 1 chainfer the edge thereof. The portion lO is then supported in position" in the opening and is then welded to section 1 as shown at 1. thus reforming section 1. .li the pen on 10 which has been removed in the early -stcps oi the process is cracked it is-only necessary to provide a new piece of metal of proper size and weld the same in position in the openingformed by the removal of the portion 10.. ,o

it has been found more practical to carry out the method just-described by electric welding as the degree of heat necessary to eilcct a practical weld can be controlled with much greater accuracy than can heat of any other welding process and a far more efficient weld obtained.

From the above description it is believed that themethod will be obvious to those skilled in the art but I desire it understood that the drawings are merely by ,way of example and that the herein described ll'ltlb od of repair is-applicable generally to any metallic double walled structure, It is fun their to be understood. that various change may be made w thin the scope of app ed claims without departing from the sol. oi the invention.

Having thus described my invention, what l claim as new anddesnfe to secure by Letters Patent is: a

1 ri TAQ} a vp 1 1- '1 no .1. A6 niche i on pairin \ioume waned metallic structures having a crack in the lower wall thereof, which comprises, re-

moving a portion oi the-upper wall above -welding which comprises weasel the crack, removing a portion of the lower wall adjacent the crack, filling the opening thus formed in the lower wall, and finally welding the portion which has been removed from the upper wall into position in said upper wall.

2. The method of repairing double-walled metallicstructures having a crack in the lower wall thereof, which Eompriscs, removing a portion of the upper wall above the crack, removing a portion of the metal of the lower wall adjacent the crack forming an opening in said well, filling the opening by welding, and finally welding the portion which has been removed irom the upper wallinto position in said upper wall.

3. The method of repairing double-walled structures having a crack in the lower wall 7 thereof, which comprises removing a p01 tion of the upper wall above the crack, re moving a portion of the lower wall adjacent the crack forming an opening ill-tile said 105%?" wall, securing a. pad to said lower wall, said pad covering said opening, filling the opening by welding, said pad being welded to the metal of the weld and the lower wall, and replacing the portion previously removed from the upper wall, and finally electrically welding said portion to said upper. wall,

4i. -1he method of repairing cracked or broken double-walled structures by welding, which comprises, removing a portion, of the upper wall above the crack or break, removing the cracked or broken surface, re-

forming the cracked or broken surface by welding, and finally replacing the portion previously removed from the upper wall and weld ng the same to the upper Wall.

5. The method of repairing cracked or broken double-walled structures by electric removing a portion' of the upper wall above the crack or break, removing the cracked or-broken-surface, forming an opening through said lower wall, securing a pad to the lower face off said lower wall, said pad covering said opening, electrically welding said pad to said lower wall and fillin said opening," and finally electrically wel ing the portion previously removed from the upper well back into position in said upper wall.

in testimony whereof I hereby afix my si nature;

some arries. 

